This invention relates to a coupler for fluid conduits that permits the rotary motion of the conduits relative to each other, and, more particularly, to such a coupler operable in a high-vacuum external environment.
It often is necessary to couple fluid conduits in a manner which permits the conduits to rotate relative to each other. An example is a cooling conduit in a rotatable sensor assembly. A flow of a liquid coolant flows from a source, through a conduit, and to a sensor mounted on a rotatable gimbal. The conduit must be rotatable to permit the gimbal to rotate.
At the present time, there are two techniques for achieving rotation in the conduit. In one, there is a joint with O-ring seals located along the length of the conduit. While operable, this approach has the shortcoming that there may be significant leakage of liquid or gas through the seal. The leakage may be particularly troublesome when the structure is operated in a high-vacuum environment such as in space. The external vacuum environment accelerates the leakage through the seal. The loss of liquid or gas may limit the life of the system due to exhaustion of the coolant, and the lost gas may adversely affect the operation of other parts of the spacecraft.
The other approach is to use a coiled tube, having no joints along its length, to convey the coolant. The tube coils and uncoils as the gimbal rotates. This conduit structure avoids leakage, but it limits the rotation of the gimbal to up to about 11/2 revolutions in either direction. This limitation on the amount of rotation may rule out this option for some applications, such as sensor systems which must track multiple objects at the same time. The conduit also adds uncontrolled drag to the rotation of the gimbal, which may adversely affect the tracking precision of the gimbaled sensor.
Thus, while operable conduit structures are known, they all have shortcomings, particularly in a vacuum environment. There is a need for an improved technique for coupling a fluid conduit to a rotatable structure. The present invention fulfills this need, and further provides related advantages.